Chemistry in Everyday Life MCQs

Solved MCQs on everyday chemistry: acids and bases, common compounds, rusting and galvanisation, fuels, polymers, hard water and soap, for SSC and railway science.

1. 1

   The chemical name of washing soda is:

   ASodium hydroxideBSodium carbonate (decahydrate)CSodium bicarbonateDCalcium carbonate

   Correct answer: B. Sodium carbonate (decahydrate)

   Washing soda is Na₂CO₃·10H₂O; baking soda is sodium bicarbonate (NaHCO₃).

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2. 2

   The chemical name usually given for bleaching powder is:

   ACalcium carbonateBPotassium nitrateCCalcium oxychlorideDSodium chloride

   Correct answer: C. Calcium oxychloride

   Bleaching powder (CaOCl₂) releases chlorine, which bleaches and disinfects water.

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3. 3

   A solution with a pH less than 7 is:

   ASaltyBBasicCNeutralDAcidic

   Correct answer: D. Acidic

   pH below 7 is acidic, 7 is neutral and above 7 is basic (alkaline).

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4. 4

   Antacids relieve indigestion by:

   Aneutralising excess stomach acidBspeeding up digestion of fatsCadding acid to the stomachDkilling bacteria

   Correct answer: A. neutralising excess stomach acid

   Antacids contain mild bases such as magnesium hydroxide that neutralise extra hydrochloric acid.

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5. 5

   Which acid is produced in the human stomach?

   AHydrochloric acidBNitric acidCSulphuric acidDAcetic acid

   Correct answer: A. Hydrochloric acid

   Hydrochloric acid helps digest proteins and kills many germs in food.

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6. 6

   Rusting of iron is an example of:

   AReductionBNeutralisationCOxidationDSublimation

   Correct answer: C. Oxidation

   Iron reacts with oxygen in the presence of moisture to form hydrated iron oxide (rust).

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7. 7

   Galvanisation protects iron from rusting by coating it with:

   ALeadBCopperCTinDZinc

   Correct answer: D. Zinc

   A thin layer of zinc keeps air and water away and corrodes first, protecting the iron.

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8. 8

   The main gas in biogas is:

   ACarbon dioxideBMethaneCOxygenDHydrogen

   Correct answer: B. Methane

   Biogas from cow dung and waste is mostly methane, with some carbon dioxide.

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9. 9

   Which fuel has the highest calorific value (energy per kilogram)?

   APetrolBWoodCCoalDHydrogen

   Correct answer: D. Hydrogen

   Hydrogen releases about 140 kJ per gram, roughly three times as much as petrol.

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10. 10

    "Dry ice" is the solid form of:

    ANitrogenBAmmoniaCCarbon dioxideDWater

    Correct answer: C. Carbon dioxide

    Solid CO₂ turns straight into gas (sublimes) at about −78 °C, without melting into a liquid.

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12. 11

    Nylon is an example of a:

    ASynthetic polymerBNatural fibreCMineralDMetal alloy

    Correct answer: A. Synthetic polymer

    Nylon, a polyamide, was one of the first fully synthetic fibres.

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13. 12

    PVC stands for:

    APolymer vinyl carbonateBPolyvinyl chlorideCPlastic vinyl compoundDPolyvinyl carbide

    Correct answer: B. Polyvinyl chloride

    PVC is used in pipes, cable insulation and window frames.

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14. 13

    Teflon is widely used for:

    AFertilisersBNon-stick coatings on cookwareCMaking glassDElectrical wires only

    Correct answer: B. Non-stick coatings on cookware

    Teflon (PTFE) is slippery and heat-resistant, so food does not stick to it.

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15. 14

    The chemical formula of ozone is:

    AH₂O₂BCO₂CO₃DO₂

    Correct answer: C. O₃

    Ozone has three oxygen atoms; the ozone layer absorbs harmful ultraviolet rays.

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16. 15

    Hard water contains dissolved salts mainly of:

    ACalcium and magnesiumBIron and copperCLead and zincDSodium and potassium

    Correct answer: A. Calcium and magnesium

    Calcium and magnesium salts stop soap from lathering and leave scale in kettles.

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17. 16

    Soap is chemically the sodium or potassium salt of:

    Acarbonic acidBmineral acidsCamino acidsDlong-chain fatty acids

    Correct answer: D. long-chain fatty acids

    Soap is made by heating fats or oils with an alkali (saponification).

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18. 17

    Stainless steel resists rusting mainly because it contains:

    AChromiumBCopperCCarbonDAluminium

    Correct answer: A. Chromium

    Chromium forms a thin, protective oxide layer; nickel is often added too.

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19. 18

    The gas that leaked in the Bhopal gas tragedy of 1984 was:

    ACarbon monoxideBMethyl isocyanateCAmmoniaDChlorine

    Correct answer: B. Methyl isocyanate

    Methyl isocyanate leaked from the Union Carbide pesticide plant in Bhopal on 2–3 December 1984.

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20. 19

    Which gas is used to ripen fruits artificially in a safe, controlled way?

    ANitrogenBNeonCEthylene (ethene)DChlorine

    Correct answer: C. Ethylene (ethene)

    Ethylene is a natural plant hormone that triggers ripening. Calcium carbide, which gives off acetylene, is banned for ripening in India.

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21. 20

    Which gas is commonly used in fire extinguishers?

    AHydrogenBOxygenCMethaneDCarbon dioxide

    Correct answer: D. Carbon dioxide

    CO₂ is heavier than air and does not support burning, so it smothers the fire.

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